JP2008230350A - Elastic crawler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain the occurrence of cutting of a lug of an elastic crawler. <P>SOLUTION: One or a plurality of grooves 15 along the circumferential direction Y of a crawler body 7 is/are formed on a grounding surface 16 of the lug 8 within a range (w) to a distance of 10% of width W in the belt widthwise direction X of the crawler body 7 toward the inside in the crawler main body belt widthwise direction X from an end part in the crawler main body belt widthwise direction X of a core bar 9, and a cross-section shape of the groove 15 is made roughly semi-circular or roughly trapezoidal with groove depth D of more than 2 mm and less than 5 mm and groove width F of more than 5 mm and less than 10 mm. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an elastic crawler used in a crawler type traveling device employed as a traveling unit of a construction machine such as a backhoe or an agricultural machine such as a tractor or a combine.

Conventionally, as an elastic crawler used in a crawler-type traveling device, a crawler body formed in an endless belt shape with rubber is provided, and a lug that is in contact with the ground is provided on the outer peripheral side of the crawler body at a circumferential interval, In the crawler body, a cored bar arranged at intervals in the circumferential direction and a tensile body arranged so as to extend in the circumferential direction of the crawler body on the outer peripheral side of the crawler body are embedded. There is a thing (refer patent document 1).
JP 2005-271710 A

  For elastic crawlers, the width of the core bar in the crawler body band width direction is shorter than the width of the crawler body band width direction, and the outer side of the elastic crawler body band direction in the crawler body band width is formed only with rubber. For example, when the end of the elastic crawler on the crawler main body width direction side (the end of the lug) rides on a curbstone or the like, the crawler main body band of the elastic crawler 6 from the core metal 9 is shown in FIG. The outer side in the width direction X is deformed in the direction indicated by the arrow A. When the deformation in the direction indicated by the arrow A occurs, the end portion of the grounding surface 16 of the lug 8 in the crawler body band width direction X of the core 9 There is a case where a tensile force acts on the portion corresponding to (B portion) and a crack is generated in the elastic crawler 6, which grows and leads to the ear piece of the lug 8 (break of the lug 8).

  In view of the above problems, an object of the present invention is to suppress the occurrence of cracks described above.

The technical means taken by the present invention in order to solve the technical problem includes a crawler main body formed in an endless belt shape by a rubber-like elastic material, and a lug that contacts the ground is provided around the outer periphery of the crawler main body. In the crawler body, the cored bar is disposed in the crawler body at intervals in the circumferential direction, and is disposed so as to extend in the circumferential direction of the crawler body on the outer peripheral side of the crawler body of the cored bar. In an elastic crawler in which a tensile body is embedded,
The circumference of the crawler body on the grounding surface of the lug is within a range from the end of the crawler body band width direction of the core bar to the inside of the crawler body band width direction to a distance of 10% of the width of the crawler body band width direction. One or a plurality of grooves along the direction are formed, and the groove has a groove depth of 2 mm or more and 5 mm or less, a groove width of 5 mm or more and 10 mm or less, and a cross-sectional shape on a plane orthogonal to the circumferential direction of the crawler body Has a substantially semicircular shape or a substantially trapezoidal shape with the grounding side as the bottom.

Also, the crawler body 7 is composed of an outer tread side rubber 17 and an inner base side rubber 18, the hardness of the tread side rubber 17 is set to 60 ° to 80 °, and the hardness of the base side rubber 18 is set. The hardness of the tread side rubber 17 is preferably set to be 5 ° or more higher.
In addition, a convex portion that bulges toward the outer peripheral side of the crawler body is provided on the outer peripheral surface side of the crawler main body between the adjacent lugs in the circumferential direction of the crawler main body and at least corresponding to the range in which the groove is formed. The rubber gauge between the outer peripheral surface of the crawler main body and the tensile body at the convex portion is T, and the rubber gauge between the outer peripheral surface of the crawler main body and the tensile body at the portion where the convex portion is not provided is t. When
It is preferable that T ≧ 1.3t.

  According to the present invention, for example, when the end of the crawler body in the width direction of the elastic crawler rides on a curbstone and a tensile load acts on the grounding surface of the lug, the tensile load is caused by the groove provided on the grounding surface of the lug. It is relieved and it can suppress that a crack arises in an elastic crawler (it can suppress causing an ear piece of a lug).

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In FIG. 4, reference numeral 1 denotes a crawler type traveling device that is employed as a traveling unit of a construction machine or an agricultural machine.
This crawler type traveling device 1 includes a sprocket 2 disposed on one side of the front and rear, an idler 3 disposed on the other side of the front and rear, and a plurality of wheels 4 disposed between the sprocket 2 and the idler 3. The track frame 5 is supported by the track frame 5 so as to be rotatable about a horizontal axis, and the sprocket 2 is rotated by the endless elastic crawler 6 around the sprocket 2, the idler 3 and the plurality of wheels 4. The sprocket 2 is rotated. By driving, the driving force is transmitted from the sprocket 2 to the elastic crawler 6 so that the elastic crawler 6 circulates and runs in the circumferential direction Y, thereby being able to run in the front-rear direction.

The elastic crawler 6 has a crawler body 7 formed in an endless belt shape by a rubber-like elastic material (rubber in the present embodiment) such as rubber, resin, and the crawler body 7 has its width direction X left and right. It is wound around the sprocket 2, the idler 3, and the roller 4 in accordance with the direction.
As shown in FIGS. 1 and 2, lugs 8 that are in contact with the ground are provided on the outer circumference side of the crawler body 7 at intervals in the circumferential direction Y and over the entire circumference.
In this embodiment, the lugs 8 are provided on both the left and right sides of the crawler body 7, and the left and right lug 8 rows are formed with a half-pitch phase shifted from the other lug 8 rows.

Further, in the crawler main body 7, a cored bar 9 disposed at intervals in the circumferential direction Y, and a resistance disposed so as to extend in the circumferential direction Y of the crawler main body 7 on the crawler outer peripheral side of the cored bar 9. A tension body 10 is embedded.
The cored bar 9 is made of a hard material such as metal, and has a central part 11 located on the center side in the left-right direction X of the crawler body 7 and extends integrally from the center part 11 to the left and right sides. It is mainly composed of a wing part 12 located on the left and right side parts of the main body 7.
In addition, a pair of left and right anti-roll-off protrusions 13 that are located on the center side in the left-right direction X of the crawler main body 7 and project toward the inner peripheral side of the crawler main body 7 are integrally formed on the central portion 11 of the core metal 9. When the wheel 4, the idler 3 and the sprocket 2 are engaged with the derailing prevention protrusion 13, the elastic crawler 6 is prevented from being derailed (the elastic crawler 6 is detached).

Further, an engagement hole 14 into which teeth of the sprocket 2 are inserted to transmit power from the sprocket 2 to the elastic crawler 6 is adjacent in the circumferential direction Y of the crawler body 7 at the center in the left-right direction X of the crawler body 7. The crawler body 7 is formed between the cored bars 9 to penetrate in the thickness direction.
The tensile body 10 is composed of a number of tensile cords such as steel cords, and the tensile cords are embedded in the crawler body 7 so as to cover the entire circumference Y and arranged side by side in the left-right direction X.
A pair of left and right tensile bodies 10 are provided on the outer peripheral side of the crawler body 7 of the left and right wings 12 of the core metal 9, and the power transmitted from the sprocket 2 to the core metal 9 is transmitted to the crawler body 7. It has a function of transmitting to the entire circumference and a function of withstanding the tension applied to the crawler body 7.

Further, both end portions in the left-right direction X of the cored bar 9 are located on the inner side (center side) in the left-right direction X with respect to the end portions in the left-right direction X of the crawler body 7. The outer end portion in the direction X (the end portion on the opposite side to the end portion on the center side in the left-right direction X of the crawler body 7) is located on the inner side in the left-right direction X with respect to the outer end portion in the left-right direction X .
Further, the corner portion formed by the ground contact surface 16 and the outer surface 20 of the lug 8 is located on the outer side in the left-right direction X than the end portion in the left-right direction X of the cored bar 9 in the present embodiment. And the outer surface 20 of the lug 8 is formed in the inclined surface which transfers to the inner peripheral side of the crawler main body 7 as it goes to the left-right direction X outward.

  A groove 15 along the circumferential direction Y of the crawler body 7 is formed from one end to the other end in the circumferential direction Y of the crawler body 7 on the outer end side in the left-right direction X of the grounding surface 16 of each lug 8. The side of the elastic crawler 6 in the left-right direction X end rides on a curb or the like, and on the portion of the grounding surface 16 of the lug 8 that corresponds to the left-right direction X end of the metal core 9 ( When a tensile load is applied to the ground 16 in the lateral direction X outer end side), the tensile load is alleviated by the groove 15, and cracks can be prevented from occurring in the elastic crawler 6. It is possible to suppress the occurrence of ear cuts.

One or a plurality of the grooves 15 are formed.
Further, the groove 15 is pulled by the ground contact surface 16 of the lug 8 when the left and right X end side of the elastic crawler 6 rides on a curb or the like and the left and right X end side of the elastic crawler 6 is elastically deformed upward. The range w in which the load is applied, that is, the range w in which the groove 15 is formed, is the width W in the left-right direction X of the crawler body 7 from the end in the left-right direction X of the core 9 toward the inner side in the left-right direction X. Within a range up to 10% of the distance.
As shown in FIG. 3, the cross-sectional shape of the groove 15 on the surface orthogonal to the circumferential direction Y of the crawler body 7 is preferably a substantially semicircular shape or a substantially trapezoidal shape with the grounding side as the bottom.

The groove 15 preferably has a groove depth D of 2 mm to 5 mm and a groove width F of 5 mm to 10 mm.
When the groove depth D <2 mm and / or the groove width F <5 mm, when a tensile force acts on the groove forming range w of the ground contact surface 16 of the lug 8, there is a case where the rubber elongation cannot be absorbed well. is there.
Further, if the groove depth D> 5 mm, the rigidity of the lug 8 is lowered and weakened.
Further, if the groove width F> 10 mm, when a tensile force acts on the groove forming range w of the ground contact surface 16 of the lug 8, a crack is generated on the inner surface of the groove 15 due to the tensile load generated on the inner surface of the groove 15. There is a case.

In addition, the crawler body 7 is configured in a two-layer structure from a tread-side rubber 17 on the outer peripheral side and a base-side rubber 18 on the inner peripheral side, and in this embodiment, the tread-side rubber 17 is the left-right direction of the core metal 9. The base rubber 18 is positioned on the inner peripheral side of the crawler main body 7 from the end in the left-right direction X of the cored bar 9 (in other words, the tread side rubber 17 and The boundary with the base-side rubber 18 is located within the width in the crawler body thickness direction at the end in the left-right direction X of the core metal blade 12).
Further, the base side rubber 18 is formed of rubber having a hardness higher than that of the tread side rubber 17.

Thus, by forming the base side rubber 18 with rubber having a hardness higher than the rubber hardness of the tread side rubber 17, the left and right direction X end side of the elastic crawler 6 rides on a curb or the like, and the left and right direction of the elastic crawler 6. When the X end portion side is elastically deformed upward, the deformation can be suppressed, whereby the tensile load acting on the left and right direction X outer end portion side of the grounding surface 16 of the lug 8 can be reduced. In addition, it is possible to suppress the occurrence of cracks in the elastic crawler 6 (ie, the occurrence of ear cutting of the lugs 8).
The tread side rubber 17 has a hardness of 60 ° (JIS A hardness) to 80 ° (JIS A hardness) (60 ° to 80 °), and the base side rubber 18 has a hardness of the tread side rubber 17. Is preferably set higher than 5 ° (JIS A hardness).

The rubber constituting the lug 8 may be the same as the tread side rubber 17 or may be a rubber having a hardness different from that of the tread side rubber 17.
The crawler main body 7 bulges toward the outer peripheral side of the crawler main body 7 between the adjacent lugs 8 in the crawler main body circumferential direction Y and on the side of the crawler main body 7 in the left and right X direction. A convex portion 19 is provided.
In the present embodiment, the convex portion 19 is formed so as to extend from one lug 8 of the lug 8 adjacent in the circumferential direction Y of the crawler body 7 to the other lug 8.

Thus, by forming the convex portion 19 on the side of the outer peripheral surface of the crawler body 7 in the left-right direction X end, the left-right direction X-end of the elastic crawler 6 rides on a curb or the like and the left-right direction of the elastic crawler 6 When the X end portion side is elastically deformed upward, the deformation can be suppressed, and thereby, the tensile load acting on the left and right direction X outer end portion side of the grounding surface 16 of the lug 8 can be reduced, It is possible to prevent the elastic crawler 6 from being cracked (the lug 8 is cut off from the ears).
Therefore, the convex portion 19 is provided at least in a portion corresponding to the range w in which the groove 15 is formed, and in the present embodiment, the left and right width is formed slightly wider than the groove forming range w. Yes.

In addition, the rubber gauge between the outer peripheral surface of the crawler body 7 and the tensile body 10 in the convex portion 19 is T, and the outer peripheral surface of the crawler main body 7 and the tensile body 10 in a portion where the convex portion 19 is not provided. When the rubber gauge in between is t (the minimum value of t is 10 mm),
It is preferable that T ≧ 1.3t.
In the present embodiment, the top portion of the convex portion 19 (the outer peripheral surface of the crawler body 7) is formed in a flat shape substantially parallel to the portion where the convex portion 19 is not formed.
Next, the conventional elastic crawler, the elastic crawler 6 according to the preferred embodiment of the present invention, and the elastic crawler according to the comparative example with respect to the preferred embodiment of the present invention are mounted on the traveling portion of the hydraulic excavator, and the effect is confirmed. Table 1 below shows the result of the test.

The test was carried out by entering the curb at an angle of 15 ° to 30 °, and when the elastic crawler 6 climbed on the curb, the hydraulic excavator was moved backward to return to the original position and again entered the curb.
In addition, when the elastic crawler 6 slipped without climbing on the curbstone, it stopped once, and the traveling device was retracted to return to the original position.
By repeating this process, the number of ear breaks occurring in the lug 8 of the elastic crawler 6 was examined.
Also, the conventional elastic crawler was prepared by embedding the core metal 9 and the tensile body 10 in one kind of rubber and integrally formed with the lug 8, and the conventional elastic crawler was run on a test. Sometimes, the number of ear cuts occurring in the lug 8 is indexed as an ear cut performance value 100, and this value is compared with the preferred embodiment of the elastic crawler 6 of the present invention and the ear cut performance of the elastic crawler of the comparative example. evaluated. Note that the smaller the number of ear cuts, the larger the value of the ear cut performance.

  Further, the preferred examples and comparative examples were tested with one groove 15 formed.

As shown in Table 1, according to this test, it was found that preferred Examples 1 to 6 of the present invention improved the ear-cut performance by 18% or more compared to the conventional example. Moreover, even if the suitable Examples 1-6 which concern on this invention were compared with Comparative Examples 1-5, it turned out that ear-cutting performance is good (ear-cutting is suppressed).
Further, by this test, the groove cutting depth D of the groove 15 formed on the ground contact surface 16 of the lug 8 is set to 2 mm to 5 mm, and the groove width F is set to 5 mm to 10 mm to improve the ear cutting performance. You can see that

Further, when the hardness of the tread side rubber 17 is set to 60 ° to 80 ° and the hardness of the base side rubber 18 is set to be 5 ° or more higher than the hardness of the tread side rubber 17, It can be seen that the performance is good.
Further, when the relationship between the rubber gauge T of the tread rubber 17 where the convex portion 19 is provided and the rubber gauge t of the portion where the convex portion 19 is not formed satisfies T ≧ 1.3 t. It can be seen that it is possible to greatly suppress ear cutting.

It is sectional drawing which cut | disconnected the elastic crawler by the surface orthogonal to the circumferential direction. It is a partial top view of the outer peripheral side of an elastic crawler. It is sectional drawing of the groove | channel cut | disconnected by the surface orthogonal to a crawler circumferential direction. It is a side view of a crawler type traveling device. It is sectional drawing of the conventional elastic crawler.

Explanation of symbols

7 Crawler Body 8 Lug 9 Core 10 Tensile Body 15 Groove 17 Tread Side Rubber 18 Base Side Rubber 19 Convex D Groove Depth F Groove Width T Rubber Gauge Between Crawler Body Outer Surface and Tensile Body at Convex t Rubber gauge between the outer peripheral surface of the crawler main body and the tensile body in the portion where no protrusion is provided X Band width direction of crawler main body (left-right direction)
Y Crawler body circumferential direction w Groove range W Crawler body width

Claims (3)

A crawler body (7) formed in an endless belt shape by a rubber-like elastic material is provided, and a lug (8) that contacts the ground is provided on the outer periphery side of the crawler body (7) at intervals in the circumferential direction (Y). At the same time, a cored bar (9) disposed in the crawler body (7) at intervals in the circumferential direction (Y), and a crawler body (7) on the outer peripheral side of the crawler body (7) of the cored bar (9). In an elastic crawler formed by embedding a tensile body (10) disposed so as to extend in the circumferential direction (Y) of
10 in the width (W) of the crawler body (7) in the width direction (X) from the end of the core bar (9) in the crawler body band width direction (X) inward. % In the range (w) up to a distance of%, one or more grooves (15) along the circumferential direction (Y) of the crawler body (7) are formed on the ground contact surface (16) of the lug (8). 15) is a cross section taken along a plane perpendicular to the circumferential direction (Y) of the crawler body (7) in which the groove depth (D) is 2 mm to 5 mm and the groove width (F) is 5 mm to 10 mm. An elastic crawler characterized by having a substantially semicircular shape or a substantially trapezoidal shape with the grounding side as the bottom.   The crawler body (7) is composed of a tread-side rubber (17) on the outer peripheral side and a base-side rubber (18) on the inner peripheral side, and the hardness of the tread side rubber (17) is set to 60 ° to 80 °. The elastic crawler according to claim 1, wherein the hardness of the side rubber (18) is set to be 5 ° or more higher than the hardness of the tread side rubber (17). On the outer peripheral surface side of the crawler main body (7), between the adjacent lugs (8) in the crawler main body circumferential direction (Y) and at least a portion corresponding to the range (w) in which the groove (15) is formed, The convex part (19) which bulges toward the outer peripheral side of (7) is provided, and the rubber gauge between the outer peripheral surface of the crawler body (7) and the tensile body (10) in this convex part (19) is T. When the rubber gauge between the outer peripheral surface of the crawler body (7) and the tensile body (10) in the portion where the convex portion (19) is not provided is t,
The elastic crawler according to claim 1, wherein T ≧ 1.3t.

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